#!/bin/sh
### quick-install-emacs --- do a halfway-decent job of installing emacs quickly

## Copyright (C) 2001-2019 Free Software Foundation, Inc.

## Author: Miles Bader <miles@gnu.org>

## This file is part of GNU Emacs.

## GNU Emacs is free software: you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.

## GNU Emacs is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.

## You should have received a copy of the GNU General Public License
## along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.


### Commentary:

## This script is mainly intended for emacs maintainer or pretesters who
## install emacs very often.  See the --help output for more details.


PUBLIC_LIBSRC_BINARIES='emacsclient etags ctags ebrowse'

AVOID="CVS -DIC README COPYING ChangeLog ~ [.]orig$ [.]rej$ Makefile$ Makefile.in$ makefile$ makefile.w32-in$ stamp-subdir [.]cvsignore [.]arch-ids [{]arch[}] [.][cho]$ make-docfile"

# Prune old binaries lying around in the source tree
PRUNE=no
# Re-install files even if they already exist
FORCE=no
# Command verbose flag
VERBOSE=''

me="`basename $0`"

# Install commands (if the user specifies the '--verbose' option, it is
# passed to these commands, so that feature only works if these commands
# implement it too)
LINK='cp -lf'
COPY='cp -f'
REMOVE='rm -r'
MKDIR='mkdir -p'

# Used to execute commands once we create them
EXEC='sh'

NAWK=/usr/bin/nawk

# avoid non-standard command output from non-C locales
unset LANG LC_ALL LC_MESSAGES

# Some messages
USAGE="Usage: $me [OPTION...] BUILD_TREE [PREFIX]"
TRY="Try '$me --help' for more information."

# Parse command-line options
while :; do
  case "$1" in
    -n|--dry-run)
      EXEC=cat; shift;;
    -p|--prune)
      PRUNE=yes; shift;;
    -P|--no-prune)
      PRUNE=no; shift;;
    --prune-only)
      PRUNE=only; shift;;
    -f|--force)
      FORCE=yes; shift;;
    -v|--verbose)
      VERBOSE="-v"; shift;;
    --help)
      cat <<EOF
$USAGE
Install emacs quickly

  -n, --dry-run              print installation commands instead of
                             executing them

  -f, --force                install even files that haven't changed
  -v, --verbose              print messages describing what is done

  -p, --prune                prune old generated files
  -P, --no-prune             don't prune old generated files (default)
      --prune-only           prune old generated files, but don't install

      --help                 display this help and exit
      --version              output version information and exit

$me install emacs "incrementally", that is, it will
install only those files that have changed since the last time it was
invoked, and remove any obsolete files from the installation
directories.  It also uses hard-links into the source and build trees to
do the install, so it uses much less space than the default Makefile
install target; however, this also means that $me can
not install onto a disk partition other than the one on which the source
and build directories reside.

Optionally, $me can also remove old versions of
automatically generated files that are version-specific (such as the
versioned emacs executables in the 'src' directory).
The latter action is called "pruning", and
can be enabled using the '-p' or '--prune' options.
EOF
      exit 0
      ;;
    --version)
      cat <<EOF
$me 1.6

Written by Miles Bader <miles@gnu.org>
EOF
      exit 0
      ;;
    -[!-]?*)
      # split concatenated single-letter options apart
      FIRST="$1"; shift
      set -- `printf '%s\n' "$FIRST" | sed 's/-\(.\)\(.*\)/-\1 -\2/'` "$@"
      ;;
    -*)
      printf '%s\n' >&2 "$me: unrecognized option '$1'"
      printf '%s\n' >&2 "$TRY"
      exit 1
      ;;
    *)
      break;
  esac
done

LINK_CMD="$LINK $VERBOSE"
REMOVE_CMD="$REMOVE $VERBOSE"

case $# in
  1) BUILD="$1";;
  2) BUILD="$1"; prefix="$2";;
  *)
    printf '%s\n' >&2 "$USAGE"
    printf '%s\n' >&2 "$TRY"
    exit 1
    ;;
esac

if test ! -d "$BUILD"; then
  printf '%s\n' >&2 "$me: $BUILD: Build tree not found"
  exit 2
elif test ! -r "$BUILD/config.status"; then
  printf '%s\n' >&2 \
    "$me: $BUILD: Not a proper build tree, config.status not found"
  exit 2
fi

CONFIG_STATUS="$BUILD/config.status"
get_config_var ()
{
  { sed -n "s/^S[[]\"$1\"[]]=\"\([^\"]*\)\"/\1/p" $CONFIG_STATUS | sed q | grep ''; } ||
  { sed -n "s/^s\(.\)@$1@\1\(|#_!!_#|\)*\(.*\)\1.*$/\3/p" $CONFIG_STATUS | sed q | grep ''; } ||
  {
    printf '%s\n' >&2 \
      "$me: $1: Configuration variable not found in $CONFIG_STATUS"
    exit 4
  }
}

test x"$SRC" = x && { SRC="`get_config_var srcdir`" || exit 4 ; }
test x"$prefix" = x && { prefix="`get_config_var prefix`" || exit 4 ; }
test x"$ARCH" = x && { ARCH="`get_config_var host`" || exit 4 ; }

VERSION=`
  sed -n 's/^AC_INIT([	 ]*emacs[	 ]*,[	 ]*\([^	 ),]*\).*/\1/p' <$SRC/configure.ac
` || exit 4
test -n "$VERSION" || VERSION=`
  sed -n 's/^AC_INIT([	 ]*GNU Emacs[	 ]*,[	 ]*\([^	 ),]*\).*/\1/p' <$SRC/configure.ac
` || exit 4
test -n "$VERSION" || { printf '%s\n' >&2 "$me: no version in configure.ac"; exit 4; }

DST_SHARE="$prefix/share/emacs/$VERSION"
DST_BIN="$prefix/bin"
DST_LIBEXEC="$prefix/libexec/emacs/$VERSION/$ARCH"

# There are various common places for the info dir to be, so try to
# use whatever's already there, defaulting to (and preferring)
# .../share/info.
#
DST_INFO=''
for D in "$prefix/share/info" "$prefix/info"; do
  if test -d "$D"; then
    DST_INFO="$D"
    break
  fi
done
DST_INFO=${DST_INFO:-"$prefix/share/info"}

maybe_mkdir ()
{
  if ! test -d "$1"; then
    $MKDIR $VERBOSE "$1" 2>&1 | sed "s/^mkdir:/$me:/" 1>&2
  fi
}

maybe_mkdir "$DST_BIN"
maybe_mkdir "$DST_SHARE"
maybe_mkdir "$DST_SHARE/site-lisp"
maybe_mkdir "$DST_LIBEXEC"
maybe_mkdir "$DST_INFO"

(  # start of command-generating sub-shell

PRUNED=""
if test x"$PRUNE" != xno; then
  for D in `ls -1t $BUILD/src/emacs-$VERSION.* | sed 1d`; do
    printf '%s\n' "$REMOVE_CMD $D"
    PRUNED="$PRUNED $D"
  done
fi

test x"$PRUNE" = xonly && exit 0

maybe_emit_copy ()
{
  if test "$FORCE" = yes || ! cmp -s $1 $2; then
    printf '%s\n' "$LINK_CMD $1 $2"
  fi
}

maybe_emit_copy $BUILD/src/emacs $DST_BIN/emacs
maybe_emit_copy $BUILD/src/emacs $DST_BIN/emacs-$VERSION

for F in $PUBLIC_LIBSRC_BINARIES; do
  maybe_emit_copy $BUILD/lib-src/$F $DST_BIN/$F
done

if test x"$SRC" = x"$BUILD"; then
  PFXS="$BUILD"
else
  PFXS="$SRC $BUILD"
fi

for SUBDIR in lisp leim etc lib-src info; do
  # defaults
  SHARED=no
  FORCED=''
  AVOID_PAT="`printf '%s\n' "($AVOID)" | tr ' ' '|'`"

  # Set subdir-specific values
  case $SUBDIR in
    lisp|leim)
      DST="$DST_SHARE/$SUBDIR"
      ;;
    etc)
      DST="$DST_SHARE/$SUBDIR"
      # COPYING is in the avoid list, but there should be a copy of it in
      # the install etc dir, so make that here.
      FORCED="$DST/COPYING"
      ;;
    lib-src)
      DST="$DST_LIBEXEC"
      AVOID_PAT="`printf '%s\n' "($AVOID ($PUBLIC_LIBSRC_BINARIES)\$)" | tr ' ' '|'`"
      ;;
    info)
      DST="$DST_INFO"
      SHARED=yes
      ;;
  esac

  for PFX in $PFXS; do
    if [ -d $PFX/$SUBDIR ]; then
      for DIR in `(cd $PFX/$SUBDIR; find . -type d -print | sed 's@^./@@')`; do
	if [ -d $DST/$DIR ]; then
	  printf '%s\n' "Directory $DST/$DIR exists"
	else
	  printf '%s\n' "Directory $DST/$DIR non-existent"
	  if [ "`printf '%s\n' "$DIR" | grep -Ev "$AVOID_PAT"`" ]; then
	    maybe_mkdir $DST/$DIR
	  fi
	fi
      done
      diff -sqr $PFX/$SUBDIR $DST
    fi
  done | $NAWK '
BEGIN {
  src_pat = "^'"$SRC"'/'"$SUBDIR"'/"
  build_pat = "^'"$BUILD"'/'"$SUBDIR"'/"
  dst_pat = "^'"$DST"'/"
  dst_pfx = "'"$DST"'/"
  avoid_pat = "'"$AVOID_PAT"'"
  force = ("'"$FORCE"'" == "yes")
  shared = ("'"$SHARED"'" == "yes")
  init_bool_array(pruned, "'"$PRUNED"'")
  init_bool_array(forced, "'"$FORCED"'")
}
function init_bool_array(array, string,  a,k)
{
  split (string, a)
  for (k in a)
    array[a[k]] = 1
}
function install(src, dst)
{
  if (! (src in pruned)) {
    cp[src] = dst;
    from[dst] = src;
    delete rm[dst];
  }
}
function update(src, dst, copy)
{
  if (src in pruned) {
    rm[dst] = 1;
    delete from[dst]
  } else {
    if (copy)
      cp[src] = dst;
    from[dst] = src;
    delete rm[dst];
  }
}
function uninstall(dst)
{
  if (!(dst in from))
    rm[dst] = 1;
}
/^Directory / {
  if ($2 ~ avoid_pat) {
    if ($NF == "exists")
      uninstall($2)
  } else
    update(0, $2, 0)
  next
}
/^Files / {
  if ($4 ~ avoid_pat && !($4 in forced))
    uninstall($4)
  else if ($NF == "identical")
    update($2, $4, force)
  else
    update($2, $4, 1)
  next
}
/^Only /  {
  pfx = $3
  sub (/:$/, "/", pfx)

  if (pfx ~ dst_pat) {
    if (! shared)
      uninstall(pfx $4)
  } else {
    subdir = pfx
    if (subdir ~ src_pat)
      sub (src_pat, "", subdir)
    else
      sub (build_pat, "", subdir)

    dst = dst_pfx subdir $4
    if (! (dst ~ avoid_pat))
      install(pfx $4, dst)
  }
  next
}
END {
  for (f in rm)
    print "'"$REMOVE_CMD"' " f
  for (f in cp)
    print "'"$LINK_CMD"' " f " " cp[f]
}
'
done

) | eval $EXEC
